Heat, Ventilation and Air Conditioning Maintenance will not only prevent expensive replacement of units but also prevent unit running cost and help in long running life of unit.
HVAC Maintenance - AC Maintenance
Check thermostat settings
Tighten all electrical connections
Lubricate all moving parts
Check and inspect the condensate drain
Check controls of the system
Clean evaporator and condenser air conditioning coils.
Check your central air conditioners refrigerant level
Clean and adjust blower components
Check all gas (or oil) connections, gas pressure, burner combustion and heat exchanger.
Inspect, clean, or change air filters